Accessory device for enlarging the area of the fin of a surfboard or similar water craft

ABSTRACT

A device that can be attached to a fin of a suf board or similar water craft. The device contains an opening ( 13 ) for receiving the fin ( 3 ). The device is made of elastic material and the area of the device is at least 1.5 times larger than the area of the fin of the surfboard or similar water craft. In one embodiment, the area of the device is 1.5 to 5 times larger that the area of the fin. In another embodiment, the area of the device is about 3 times larger than the area of the fin. The device may be equipped with clamping means for securely fixing the device to the fin.

TECHNICAL FIELD

This invention relates to the field of sports equipment and recreational devices; more specifically it concerns the device, which enables to increase the stability and improve the steerability of a surfboard or similar water craft.

BACKGROUND ART

Known are surfboards with fins of different shape. U.S. Pat. No. 6,394,865 describes a cover for a surfboard fin which is pulled on the fin when it is necessary to transport or store the surfboard. U.S. Pat. No. 4,325,154 describes a plastic fin. U.S. Pat. No. 5,306,188 describes covering the fin with soft material cover to avoid possible injuries caused by the fin to the swimmers.

General deficiency of the described solutions is the fact that the surfboards equipped with that kind of fins are not stable and are difficult to steer for the users with fewer skills.

DISCLOSURE OF THE INVENTION

The objective of the invention is to provide an accessory device for improving the steerability and increase the stability of a surfboard or similar water craft.

The objective is achieved with a device that can be attached to a fin of a surfboard or similar water craft. The device contains an opening for receiving the fin. The device is made of elastic material and the area of the device is at least 1.5 times larger than the area of the fin of the surfboard or similar water craft. In one embodiment, the area of the device is 1.5 to 5 times larger than the area of the fin. In another embodiment, the area of the device is about 3 times larger than the area of the fin.

The device, that is self-adhesive or, if needed, attached to the surface of the fin of the surfboard or similar water craft, increases the area of the fin, as the result of which the lateral resistance of water on the surfboard or similar water craft increases, the drift decreases and it is easier to sail upwind. Use of the device helps to avoid the surfboard turning upwind too easily (quickly). At low speeds, when the surfboard sits deeply in the water, the centre of the lateral resistance is more on the stern side in case the device is used than without using it. The more to the stern side the centre of the lateral resistance is located, the more difficult and slower the surfboard turns upwind.

Using the device increases the rectilinear resistance of water resulting in lower speed but for beginners the stability is more important than losing a little speed.

The device also serves as a cover/case for the fin. Hence it protects the fin from mechanical damage in water as well as on land.

The device is elastic and with sufficiently wide opening to fit fins of different size and shape. That kind of elastic cover makes the fin safer for the ambient environment since the fin itself is very rigid and can injure people or animals or damage things in bumping into them. If the fin is surrounded with the device, then in collision the device deforms due to elasticity and slips a little backwards on the fin. As the result, the strike on the collision disperses and softens, and hence the safety increases.

To avoid separating of the device from the surfboard when using it, it is possible to supply the device with a fastener at the opening mouth of the device (i.e. surfboard side end), e.g. with a clamp.

The device can be easily attached to and removed from the fin. No holes must be made to the fin or other supplies nor modified otherwise.

For a beginner surfer the device described in this invention gives the opportunity to sail with a surfboard for advanced surfer. When skills increase, the device can be removed.

Another objective is a method for improving the steerability and increase the stability of a surfboard or similar water craft.

The objective is achieved by increasing the area of a fin of the surfboard or similar water craft by attaching to the fin a device, made of an elastic material, and having an area at least 1.5 times larger than an area of the fin. More preferably, the fin has an area 1.5 to 5 times larger than the fin. Most preferably, the area of the fin is about 3 times larger than the area of the fin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the surfboard's fin and the device according to one embodiment of the invention.

FIG. 2 is a side view the device attached to the fin.

FIG. 3 is a cross section of the device attached to the fin.

FIG. 4 shows a top view of the device and the fin with a clamp for attaching the device to the fin.

MODES FOR CARRYING OUT THE INVENTION

The invention is now illustrated by reference to the enclosed drawings. The device 1 for improving the steerability and increasing the stability of a surfboard is a cover attached to the fin 3 of the surfboard 2. The device is manufactured from two side elements 11 and 12 (see FIG. 3) connected with each other at their edges, thereby leaving an opening 13 for receiving the fin when the device is pulled on the fin. The ratio of the area of the fin and the device is approximately 1:3.

The device may be manufactured in one piece or by connecting two side elements at their edges by any of known suitable technology. In main part the device is manufactured from tough and elastic material, e.g. elastic plastic material such as polyethylene (PE) or polypropylene (PP). The material is tough and elastic enough, if the device is able to retain its fin-like shape when the board is used in water. Preferably, the material is selected so that its specific gravity is less than 1, i.e., the material is buoyant. It is useful when the device escapes from the fin.

The device may contain a clamp 4 near to the opening for securely fixing the device to the surfboard's fin 3.

The clamp 4 has two longitudinal strips 5 between which the fin is screwed with bolts 6, washers 7 and nuts 8 whereas on one side the strip has grooves for the bolt heads and the other side has nut shape grooves for concealing the nuts and hindering their rotation and decreasing the resistance of water. To increase the frictional force, the inside of the strips is covered with rubber 9.

Below the clamp on the inner surface of the device there are support extrusions, e.g., in the form of strips 10 for fixing the device so that the fin is symmetrically inside the device. The device holds around the fin and according to the dimensions of the fin it is more or less deformed.

The outer surface of the device is by shape and finishing streamlined so that in moving forward in the water the water resistance is as small as possible.

In case of alternative clamp design the rigidity of clamp strips is increased by adding a steel strip.

In simpler case the device is made so that the surfboard side of the device is more rigid than the rest of the device thanks to which the self-adhesiveness of the device to the fin is achieved. In that case the clamp is not used.

Much better steerability, stability and diminished drift is achieved with the help of the device attached to the surfboard.

The exemplary embodiments presented herein illustrate the principles of the invention and are not intended to be exhaustive or to limit the invention to the form disclosed; it is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. 

1. An accessory device for improving the steerability and increasing the stability of a surfboard or similar water craft said device comprising; two side elements connected to each other at their edges; and an opening surrounded by the side elements for receiving a fin of the surfboard or similar water craft, wherein the device is made of an elastic material and the area of the device is at least 1.5 times larger than the area of the fin and the device comprises deformable extrusions within the device for supporting and holding the device on the fin.
 2. The device as in claim 1, wherein the deformable extrusions are in the form of strips that are substantially parallel with the axis of the fin.
 3. The device as in claim 2, wherein an outer surface of the device is streamlined by shape and finishing for reducing water resistance.
 4. The device as in claim 3, the device comprises clamping means near to the opening for attaching the device to the fin.
 5. The device as in claim 4, wherein an end of the device closer to the surfboard is made more rigid than the rest of the device.
 6. A method for increasing the stability of a surfboard or similar water craft, the method comprising increasing an area of the fin by a device attached over the fin, characterized in that the surface area of the device is at least 1.5 times larger than the surface area of the fin.
 7. The method as in claim 6, comprising fixing the device removably to the fin by clamping means integrated to the device. 